A randomised placebo controlled trial has shown that adding a nightly mesalazine enema improves remission rates in patients with extensive ulcerative colitis who are already being treated with the oral preparation. After eight weeks, nearly 90% of those receiving combined treatment had improved (44% in remission) compared with under 70% of those having placebo enemas (34% in remission). Treatment was safe and well accepted, so should be considered as first line for those with colitis extending beyond the splenic flexure.